340 cam specs?

Not measured at .004.
Probably Engle; I recall it was in a plain white box with a Hughes sticker on it. but I sorta recall seeing Engle somewhere on the cam, not sure.
That curve comes from the Hughes site. I built a very similar build, except
My;OOTB Eddies,to their stage II 596s
My; 10.85 Scr to their ,unspecified, but you can see for yourself by the curve, probably not close to the borderline
My; AirGap/ Holley 750DP, to their Torquer II/ Eddie 750
And the rest is mostly a wash

Can't speak to the dip. I wondered about it too, but since it ain't there on mine in real life, I chalked it up to the AVS type carb, or the tip-in, but IDK
I can't speak to the torque peak being so high either, and so close to the power peak; that look's wonky.
But I can tell you that on mine, I can floor it from cruising, anywhere between 45 and 55 mph in 6.06 effective road gear, and it breaks the 295s loose. This with a 4-speed in 1.92 second gear, and 3.55s, with 27" tires. So 50mph would be 4240 rpm. It's a honey of a combo, altho, it's pretty hard on gas. Once it's spinning, it spins ; some say still hazing the tires at the top of the Eighth, with 325/50-15 BFG DRs.I didn't see it, but the tach was stuck on 7000 the whole way; I thought the clutch was slipping. Hyup a real sweetheart street combo.